The Terrain is the GMC vehicle we hold the most transmissions for — more than the Sierra, in fact — and it is also the one where the RPO code does the most work. GM split these units not only by engine and drivetrain but by final drive ratio, so a 2014 Terrain can carry a 3.39-ratio unit under opt F07 or a 2.77-ratio unit under opt D70, and our listings carry those codes exactly as the feed gives them.
GMC Terrain Used Transmissions — transmission options by generation
| Years |
Transmission |
Type |
Notes |
| 2010–2017 |
6T45 |
6-speed auto |
Behind the 2.4 Ecotec — opt MH7 / MH2 |
| 2010–2017 |
6T70 |
6-speed auto |
Behind the 3.0 and 3.6 V6 — opt MHC / MH4 |
| 2010–2017 (AWD) |
6T45 / 6T70 AWD |
6-speed auto |
Different output and transfer unit |
| 2012–2017 |
6T70 / 6T75 |
6-speed auto |
Ratio split: opt F07 is 3.39, opt D70 is 2.77 |
| 2018–2024 |
6T45 |
6-speed auto |
Behind the 1.5 turbo |
| 2018–2024 |
9T50 / 9T60 |
9-speed auto |
Behind the 2.0 turbo |
| 2018–2019 |
6-speed auto |
diesel |
Behind the 1.6 turbo diesel — low volume |
How to pick the right one
Read the RPO code off the glovebox sticker and give it to us with the model year. On this vehicle the code also encodes the final drive ratio, and that matters: fitting a 2.77-ratio unit where the car had 3.39 changes the gearing and the speedometer calibration. Then tell us front-wheel drive or all-wheel drive, because the all-wheel-drive versions carry a different output and transfer unit. The Chevrolet Equinox of the same years uses the same transmissions, so a correctly coded Equinox unit fits and widens the pool.
What usually fails on these transmissions
The 6T70 has one signature failure and it is worth recognising early: the wave plate inside the 3-5 reverse clutch assembly fractures, which takes third, fifth and reverse at the same time. The warning is a flare on an upshift or a shudder before that, and once the plate goes the debris circulates. The 6T45 is the lighter unit and what comes in on those is the torque converter and the pump. On the 9T50, the complaint is shift quality rather than failure, and GM issued recalibrations, so a rough-shifting one is worth a software check first.
What ships with every unit
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Pressure tested with the solenoid readings recorded, and the fluid condition inspected and reported.
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Fitment matched — send us the model year, engine, drivetrain and the RPO option code or ID tag and we confirm the part before the order ships.
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Written warranty on every transmission, with labour coverage available.
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Free freight anywhere in the lower 48, crated on a pallet to a commercial address or a terminal.
The Chevy Equinox uses the same units. Replacing the engine too? See our GMC used engines. Full terms are in the transmission warranty policy, and the complete catalogue is at used transmissions.
GMC Terrain used transmissions - frequently asked questions
Which transmissions did the GMC Terrain use?
Across 2010 to 2024 the GMC Terrain was built with 6T45, 6T70, 6T45 / 6T70 AWD, 6T70 / 6T75, 9T50 / 9T60 and 6-speed auto. The table above lists which one belongs to each generation, with the transmission designation and option code that identifies it.
How do I identify the right transmission for my GMC Terrain?
Four things decide it: model year, engine, drivetrain, and the option or RPO code. That code is the one most people do not have to hand and the one that settles it - on a GM vehicle it is on the glovebox or door-jamb sticker, on a Chrysler it is on the build sheet, and on a Ford it is on a tag on the case. Send us the VIN and the code and we confirm the unit before anything ships.
Will a transmission from a different year fit my GMC Terrain?
Read the RPO code off the glovebox sticker and give it to us with the model year. On this vehicle the code also encodes the final drive ratio, and that matters: fitting a 2.77-ratio unit where the car had 3.39 changes the gearing and the speedometer calibration.
What usually fails on these transmissions?
The 6T70 has one signature failure and it is worth recognising early: the wave plate inside the 3-5 reverse clutch assembly fractures, which takes third, fifth and reverse at the same time. The warning is a flare on an upshift or a shudder before that, and once the plate goes the debris circulates.
What comes with a used GMC Terrain transmission?
Every transmission is pressure tested with the solenoid readings recorded and the test sheet ships in the box. The unit is matched to your VIN and option code before the order goes out, carries a written warranty with labour coverage available, and freight is free anywhere in the lower 48.
